Dying in your sleep: thank evolution.

When I first started in respiratory therapy all I knew about sleep was that it was something to be coveted and craved, especially after running your tail off on a double (16 hour) shift. I know now that there were pioneers in this field who even predated my 40 years in health care but I didn't know about them for a long time ... people like Kleitman, Dement and Rechtshaffen and Kales to name but a few. These names were meaningless and unknown to me. But I always harbored a sneaking suspicion that something went wrong, really dreadfully wrong after we fell asleep. For one thing, here was my father whose snoring and struggling to breathe was legendary. We all noticed, including him, that the snoring would be more obnoxious and much louder with longer periods of breathlessness if he had a glass of wine or a beer in the evenings with dinner. But we didn't think much more of it as kids. Then, he woke up one morning about 6 AM, got out of bed and promptly died of a massive heart attack. He was 51. Okay, he had a heart condition which was bound to get him sooner or later and an autopsy confirmed it for all of us.

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After my third year in college, I started working as staff, setting up oxygen, giving IPPB treatments and putting patients on Bird Mark7 respirators. It was then that I was exposed, on a daily basis, to sick people, people whose lives literally hung in the balance. Whenever someone had a witnessed cardiac arrest or was found collapsed and clinically dead a code was called and everyone rushed to the patient to see if they could revive them. But I still didn't notice that an inordinate number of patients choose between 4 and 7 AM to do this. One morning, during that time frame, I had three consecutive and two simultaneous code calls during those hours. What was it about the end of the night with so many people dying about that time of day? And still others, safely tucked in bed in the middle of the night decided to leave as well. Not out shoveling snow or engaging in some other strenuous exercise as some are doing when deaths strikes .... but at rest, calm and asleep. Maybe some with a beer or two on board or a sleeping pill to help them get comfortable. I still didn't get it and neither did many others. But some medical professionals were starting to notice and this led to the NOTT trials which was the biggest thing since talking movies. No one can tell me the champion runner Florence Joyner, who died in her sleep, didn't have SAHS. But some will be quick to point to Jim Fixx's untimely death while out running, an exercise he promoted as essential to good health.

Thousands of people were placed on low-flow (1-4 LPM) nasal oxygen while they were asleep. NOTT stood for "Nocturnal Oxygen Therapy Trial." Sure enough, mortality was higher among those who did not receive oxygen during sleep compared with those who did. These results were earth shaking and led to major shifts in the way oxygen therapy was prescribed (from the old standard order for 6 LPM via N/C--far too much and unnecessary to boot) and spawned an industry predicated on renting out oxygen concentrator devices to patients at home so that one less thing would kill them while they sleep: severe hypoxia. The reasons for the hypoxia were universally chalked up to the usual suspects which were either chronic obstructive pulmonary disease, a diffusion defect or some vague notion that there was a sleep related hypoventilation syndrome. Nobody realized that perhaps patients were not getting enough oxygen because they simply could not inhale due to obstruction of the airway by their own anatomy. The results of NOTT reasoned that if supplemental O2 were given, this would protect patients during sleep but fortunately there were some researchers, most prominently Dr. Colin Sullivan of Australia, who were not entirely convinced with this assessment. So, while we were happily placing hundreds of thousands of patients on nocturnal low flow O2, many still continued to die in the middle or the end of the night. At my last respiratory job, before I became involved in sleep medicine, I was assigned to perform A.M. pulse ox rounds and any patient whose room air pulse ox was higher than 85%, but had nasal oxygen at the bedside, was discontinued. Each day, probably between 33% and 50% of all the patients who used oxygen the night before were miraculously cured and their O2 discontinued based on these diurnal rounds. I then was transferred to the overnight shift. We didn't do pulse ox rounds but we were called to do pulse ox's upon a doctor's order or if the nurse was worried about a patient's breathing in any way. Carefully placing the probe on patients who were asleep or half asleep soon revealed that many of them had sats below 85%, and some well below this cut off. These patients were thus candidates for oxygen and in some cases intubation and even a ventilator if a blood gas confirmed there was a problem. What was going on here? These same people, well awake in the AM had higher oxygen saturations than they had at night while they were asleep or at least partially asleep.

Dr. Sullivan spent years attacking the problem from its anatomical aspects and developed CPAP as a means of overcoming that anatomy. Basically, human beings are being screwed by their own anatomy, anatomy evolved over millions of years. The problems, as we all know, are the anatomical structures in the posterior oro-pharynx: the uvula, the tonsils and in some cases the adenoids.

Is dying in your sleep always due to sleep apnea and hypopnea syndrome? Certainly not. Just most of the time, especially when it involves sudden and unexpected cardiac or respiratory arrest. Is dying "peacefully" in your sleep a bad thing? No, not necessarily. But as a preventable cause of death it could be considered as such. Having a cursory exam of the posterior oral cavity, answering a few questions and then, if indicated, being tested for sleep related breathing problems and titrated on CPAP or perhaps even having surgery to open up the airway might just lead to one less thing that will kill us and more sping in our step during the daylight hours.

by Steven Grenard RRT, RPSGT